According to character designer Takaya Imamura, each of the original Star Fox team members were modeled after his fellow Nintendo staff members at the time:

•Fox was based on Shigeru Miyamoto, with Miyamoto said to have a fox-like face.
•Falco was based on Tsuyoshi Watanabe, as the development team laughed over how his nose stuck out like a beak.
•Peppy was based on Katsuya Eguchi, with Eguchi said to have a mouth like a hare.
•Slippy was based on Yoichi Yamada, with Yamada said to have large, round eyes.

Imamura has also stated that he based Andross on his "boss at the time". It remains unknown who at Nintendo he is specifically talking about, though it's been long rumored that Andross was intended as a caricature of then-Nintendo president Hiroshi Yamauchi, who was known for his cutthroat and ruthless ways. However, it's also been speculated that Imamura is referring to Hiroshi Ikeda, the then-manager of Nintendo R&D4 (later EAD) who was also Miyamoto's boss, though it's worth pointing out that Ikeda had stepped down from his position in 1992.

In the original Star Fox on SNES, Venom was said to be a beautiful, green planet in the vein of Corneria before Andross, after being banished by Corneria due to his dangerous experiments, invaded and ruined it, transforming it into a dark, polluted world of military machines, all while enslaving its inhabitants who he drafted into his new army. Star Fox 2's Venom stage on Expert mode would actually depict Venom in its lush green state again, indicating that it was being terraformed back into its original state.

Star Fox 64 would essentially retcon all of this, and claim that Venom was already a desolate wasteland to begin with, which is the entire reason General Pepper banished Andross there after the latter nearly destroyed Corneria with his weapons. That being said, Star Fox Command would later reveal that during his banishment on Venom, Andross had actually created a terraforming device that he planned on using upon Venom as a means to transform it into a beautiful green world similar to Corneria, for prosperity and to also give his heirs and descendants a home to live happily in. This is essentially an inverse of his original SNES backstory, where he's now trying to save Venom and turn it into a hospitable world, as opposed to invading and transforming it into a polluted wasteland.

A 3D polygonal model based on the Arwing from the first Star Fox was discovered within Star Fox 64 3D's files. It is not known if it had anything to do with Q-Games' pitch to Nintendo of a Star Fox SNES remake that was ultimately rejected, though it's worth pointing out that that occurred after Star Fox 64 3D's release.

During the development of the original Star Fox, character designer Takaya Imamura originally wanted to make the characters generic humans and aliens, similar to his character designs from F-Zero. It was Shigeru Miyamoto who convinced him to instead make them anthropomorphic animals, as he wanted the game's aesthetic to stand out from every other science fiction property coming out at the time.

Fox in particular being a fox was inspired by the Fushimi Inari-taisha shrine located near Nintendo's offices.